A.    COOKING METHODS – MERITS AND DEMERITS

 

Food preparation is an important step in meeting the nutritional needs of the family.  Food has to be pleasing in appearance and taste in order to be consumed.  Foods like fruits, vegetables and nuts can be eaten raw but most foods are cooked to bring about desirable changes.  The process of subjecting food to the action of heat is termed as cooking.

 

Objectives of Cooking

1. Cooking sterilizes food:  Above 40° C the growth of bacteria decreases rapidly.  Hence food is made safe for consumption.

2. Cooking softens the connective tissues of meat and the coarse fibre of cereals, pulses and vegetables so that the digestive period is shortened and the gastro intestinal tract is less subjected to irritation.

3. Palatability and food quality is improved by cooking – Appearance, flavour, texture and taste of food are enhanced while cooking.

4. Introduces variety – Different dishes can be prepared with the same ingredients.  (Eg.) Rice can be made into biriyani and kheer.

5. Increases food consumption – Cooking brings about improvement in texture and flavour thereby increasing consumption of food.

6. Increases availability of nutrients – Example in raw egg, avidin binds biotin making it unavailable to the body. By cooking, avidin gets denatured and biotin is made available.

 

COOKING METHODS

Heat is transferred to the food during cooking by conduction, convection, radiation or microwave energy.

Cooking takes place by moist and dry heat.  Moist heat involves water and steam.  Air or fat are used in dry heat.

 

1. MOIST HEAT METHODS

    a. Boiling:

Boiling is a method of cooking foods by just immersing them in water at 100° C and maintaining the water at that temperature till the food is tender.  Rice, egg, dhal, meat, roots

and tubers are cooked by boiling.

Merits

1. Simple method -  It does not require special skill and equipment.

2. Uniform cooking can be achieved.

Demerits

1. Continuous excessive boiling leads to damage in the structure and texture of food.

2. Loss of heat labile nutrients such as  B and  C vitamins if the water is discarded.

3. Time consuming – Boiling takes more time to cook food and fuel may be wasted.

4. Loss of colour – water soluble pigments may be lost.

 

b. Stewing

It refers to the simmering of food in a pan with a tight fitting lid using small quantities of liquid to cover only half the food.  This is a slow method of cooking.  The liquid is brought

to boiling point and the heat is reduced to maintain simmering temperatures (82°C- 90° C).  The food above the liquid is cooked by the steam generated within the pan.  Apple, meat

along with roots, vegetables and legumes are usually stewed.

Merits

1. Loss of nutrients is avoided as water used for cooking is not discarded.

2. Flavour is retained.

Demerits

1. The process is time consuming and there is wastage of fuel.

 

c. Steaming:

It is a method of cooking food in steam generated from vigorously boiling water in a pan.

The food to be steamed is placed in a container and is not in direct contact with the water or liquid. Vegetables can be steamed.

Merits

1. Less chance of burning and scorching.

2. Texture of food is better as it becomes light and fluffy.

3. Cooking time is less and fuel wastage is less.

4. Steamed foods like contain less fat and are easily digested and are good for children, aged and for therapeutic diets.

5. Nutrient loss is minimized.

Demerits

1. Steaming equipment is required.

2. This method is limited to the preparation of selected foods.

 

d. Pressure cooking:

When steam under pressure is used the method is known as pressure cooking and the equipment used is the pressure cooker.  In this method the temperature of boiling water can be raised above 100° C.  Rice, dhal, meat, roots and tubers are usually pressure cooked.

Merits

1. Cooking time is less compared to other methods.

2. Nutrient and flavour loss is minimised.

3. Conserves fuel and time as different items can be cooked at the same time.

4. Less chance for burning and scorching.

5. Constant attention is not necessary.

Demerits

1. The initial investment may not be affordable to everybody.

2. Knowledge of the usage, care and maintenance of cooker is required to prevent accidents.

3. Careful watch on the cooking time is required to prevent over cooking.

 

e. Poaching:

This involves cooking in the minimum amount of liquid at temperatures of 80° C - 85° C that is below the boiling point. Egg and fish can be poached.

Merits

1. No special equipment is needed.

2. Quick method of cooking and therefore saves fuel.

3. Poached foods are easily digested since no fat is added.

Demerits

1. Poached foods may not appeal to everybody as they are bland in taste.

2. Food can be scorched if water evaporates due to careless monitoring.

3. Water soluble nutrients may be leached into the water.

 

f. Blanching:

In meal preparation, it is often necessary only to peel off the skin of fruits and vegetables without making them tender.

This can be achieved by blanching.  In this method, food is dipped in boiling water for 5 seconds to 2 minutes depending on the texture of the food. This helps to remove the skin or peel without softening food.

Blanching can also be done by pouring enough boiling water on the food to immerse it for some time or subjecting foods to boiling temperatures for short periods and then immediately immersing in cold water.  The process causes the skin to become loose and can be peeled off easily.

Merits

1. Peels can easily be removed to improve digestibility.

2. Destroys enzymes that bring about spoilage.

3. Texture can be maintained while improving the colour and flavour of food.

Demerits

1. Loss of nutrients if cooking water is discarded.

 

2. DRY HEAT METHODS

a. Roasting:

In this method food is cooked in a heated metal or frying pan without covering it. 

Merits

1. Quick method of cooking.

2. It improves the appearance, flavour and texture of the food.

3. Spices are easily powdered if they are first roasted.

Demerits

1. Food can be scorched due to carelessness.

2. Roasting denatures proteins reducing their availability.

 

b. Grilling:

Grilling or broiling refers to the cooking of food by exposing it to direct heat.  In this method food is placed above or in between a red hot surface.  Corn and chicken can be prepared by this method.

Merits

1. Enhances flavour, appearance and taste of the product.

2. It requires less time to cook.

3. Minimum fat is used.

Demerits

1. Constant attention is required to prevent charring.

 

c. Toasting:

This is a method where food is kept between two heated elements to facilitate browning on both sides.  Bread slices are cooked by toasting.

Merits

1. Easy and quick method.

2. Flavour improved.

Demerits

1. Special equipment required.

2. Careful monitoring is needed to prevent charring.

 

d. Baking:

 In this method, the food gets cooked in an oven or oven-like appliance by dry heat.  The temperature range maintained in an oven is 120°C– 260°C.

The food is usually kept uncovered in a container greased with a fat coated paper. Bread, cake, biscuits, pastries and meat are prepared by this method.

Merits

1. Baking lends a unique baked flavour to foods.

2. Foods become light and fluffy – cakes, custards, bread.

3. Certain foods can be prepared only by this method – bread, cakes.

4. Uniform and bulk cooking can be achieved.  Eg. bun, bread.

5. Flavour and texture are improved.

6. Variety of dishes can be made.

Demerits

1. Special equipment like oven is required.

2. Baking skills are necessary to obtain a product with ideal texture, flavour and colour characteristics.

3. Careful monitoring needed to prevent scorching.

 

e. Sauteing:

 Sauteing is a method in which food is lightly tossed in little oil just enough to cover the base of the pan.  The pan is covered with a lid and the flame or intensity of heat is reduced.

The food is allowed to cook till tender in its own steam.

The food is tossed occasionally, or turned with a spatula to enable all the pieces to come in contact with the oil and get cooked evenly.

The product obtained by this method is slightly moist and tender but without any liquid or gravy.  Foods cooked by sauteing are generally vegetables which are used as side dishes

in a menu.  Sauteing can be combined with other methods to produce variety in meals.

Merits

1. Takes less time.

2. Simple technique.

3. Minimum oil is used.

Demerits

1. Constant attention is needed as there is chance of scorching or burning.

 

f. Frying:

 In this method, the food to be cooked is brought into contact with larger amount of hot fat.  When food is totally immersed in hot oil, it is called deep fat frying.  Samosa and chips are examples of deep fat fried foods.  In shallow fat frying, only a little fat is used and the food is turned in order that both sides are browned.  Eg. Omlette, cutlets,  parathas.

Merits

1. Very quick method of cooking.

2. The calorific values of food is increased since fat is used as the cooking media.

3. Frying lends a delicious flavour and attractive appearance to foods.

4. Taste and texture are improved.

Demerits

1. Careful monitoring is required as food easily gets charred when the smoking temperature is not properly maintained.

2. The food may become soggy due to too much oil absorption.

3. Fried foods are not easily digested.

4. Repeated use of heated oils will have ill effects on health.

 

3. COMBINATION OF COOKING METHODS

Braising :

Braising is a combined method of roasting and stewing in a pan with a tight fitting lid.  Flavourings and seasonings are added and food is allowed to cook gently. 

 

4. MICROWAVE COOKING

Microwaves are electromagnetic waves of radiant energy with wave lengths in the range of 250 x 106 to 7.5 x 109 Angstroms.

The most commonly used type of microwave generator is an electronic device called a magnetron which generates radiant energy of high frequency.

A simple microwave oven consists of a metal cabinet into which the magnetron is inserted.  The cabinet is equipped with a metal fan that distributes the microwave throughout the

cabinet.  Food placed in the oven is  heated by microwaves from all directions.

 

Moist foods and liquid foods can be rapidly heated in such ovens.  Food should be kept in containers made of plastic, glass or china ware which do not contain metallic substances.

These containers are used because they transmit the microwaves but do not absorb or reflect them.

Merits

1. Quick method – 10 times faster than conventional method. So loss of nutrients can be minimized.

2. Only the food gets heated and the oven does not get heated.

3. Food gets cooked uniformly.18

4. Leftovers can be reheated without changing the flavor and texture of the product.

5. Microwave cooking enhances the flavour of food because it cooks quickly with little or no water.

Demerits

1. Baked products do not get a brown surface.

2. Microwave cooking cannot be used for simmering, stewing or deep frying.

3. Flavour of all ingredients do not blend well as the cooking time is too short.

 

5. SOLAR COOKING

Solar cooking is a very simple technique that makes use of sunlight or solar energy which is a non-conventional source of energy.

Solar cooker consists of a well insulated box which is painted black on the inside and covered with one or more transparent covers.

The purpose of these transparent covers is to trap heat inside the solar cooker.  These covers allow the radiation from the sun to come inside the box but do not allow the heat from

the hot black absorbing plate to come out of the box.  Because of this, temperature  up to 140°C can be obtained which is adequate for cooking.

Merits

1. Simple technique – requires no special skill.

2. Cost effective as natural sunlight is the form of energy.

3. Original flavour of food is retained.

4. There is no danger of scorching or burning.

5. Loss of nutrients is minimum as only little amounts of water is used in cooking.

Demerits

1. Special equipment is needed.

2. Slow cooking process. 

3. Cannot be used in the absence of sunlight – rainy season, late evening and night.

 

 

QUESTIONS

Part- A

Fill in the blanks:

1. ________ is a method of cooking foods by just immersing then in water at 100º C

2. Simmering of  food in a pan with a tight fitting lid using small quantities of liquid to cover only half the food is known as___________

3. When steam under pressure is used the method is known as     _________

4.  ___________ is a method use to prepare cakes.

5. When food is totally immersed in hot oil, it is called     _________.

6.  ________ is a combined method of roasting and stewing in a pan with a tight fitting lid

 

Part- B

Write short answers

1. What are the objectives of cooking food?

2. Bring out the differences between stewing, steaming and sauteing.

3. What is the best method of preparing rice and dhal?  Justify your choice of cooking method.

4. Write a note on solar cooking and its merits and demerits

 

Part- C

Write detailed answers

1. Compare the various moist heat methods of cooking. Highlight the merits and demerits of each type.

2. Give a brief account about the principles, merits and demerits of microwave cooking.

3. Discuss the dry heat methods of cooking?